George p



thereo f. u s t p My invention relates to means for joining one or like many others whichl involve ,cutting threads on the tubes and variously welding and enlarging, is too `means of carrying out my invention, and will after wards desgnatethe point which I believe to'be new.

specification. l

ends andthe adjacent parts, the middle being reprevention is applied.

` showing the construction which I prefer for the stayl score in both the tube end and the thimble at the leftipartsfin all the figures. l

"anni @lilium A cEoRcEP. -HUNT, or THE UNITED sTATEs NAVY.

Letters Patent No. 100,531,1ZatedV March 8, .1870.

TUBE-resumir@ PoR STEAMGENERATQRS.

.- The Schedule referred to in these Letters Patent and making part of the same To all whom it may concern Be it known that I, GEORGEP. HUNT, formerly of New York, now ofthe United States navy, temporarily located at rthe navy yard in Charlestown, Massachusetts, have invented cert-ain new and useful Improvements in` Tube-Fastenings for Steain-Boilers and Analogous Constructions; and I do hereby de-v clare that the following is a full and exact description bth ends of the tubes to the tube-sheets, or to the material, bylwhatevcr name it may be denominated, in which' the tnbe is set or secured.

Double-threaded taper thiinbles 'have beeuapplied on threadedt-ubes, as shown in the patent of, Howell & Birdsell, January 26, 1854, but such construction,

expensive to be generally adopted. 4

I have discovered that a plain thimble may be compressed bodily upon a plain tube, and have wrought ought the idea, so as to avoid all the labor of threading the tubes and preserve the full size and strength of the tpbe to the extreme end. f

I will proceedto describe what I-con`sider the best Theaccompanying drawings form a part of this` Figure 1 represents my invention as applied at one end ofthe tube, the endon the left.

Theopposite end of the tubeis'represented as secured' by previously-known means. i l Figure 1 is a longitudinal section through the two sented as broken' away.

Figure 1P is a'n'endview ofthe end to which my in- Figure 1" shows the opposite end.

Figure 2 `is a corresponding longitudinal section,

tubes distributedamong the others, and gs. 2 and .l"4 are end viewsthereof.` 1 I do not' claim these stay-tubes as new, except the hand end.

In other Words, lig. 2`and accompanying end views, contain a part only of my invention. y j

Similar letters of reference` indicate corresponding Injig. 1, and its accompanying end views, thetnbe is unthreaded orf plain, both onits exterior and interior surfaces. y

The tube is represented byA;

The tube-sheets are represented by B1 B2 The ordinary internal ihimble is represented by C; and

`A'peculiar thimble constructed and arranged aci siderably larger than the tube.

The tube lis first inserted loosely at each end, then a thimble, D, -cylindrical on its inner surface, and only a very little larger-than the tube, so'as to allow of being slipped or driven thereon, and tapering and threaded ou its exterior, having been applied on the end of the tube, as represented, is turned forcibly around so that its threads match the threads previously produced by the tapering tap.

The exterior of the thimble D' is threaded in aform `tapering to correspond to the hole before described,

and by turning the` tapering thiinble either alone or with the tube, it is caused to tit Within the threads in the tube-sheetsB. It tits at iirst loosely, then snugly, and at last very tightly.

'lhis tightness causes the material of the thimble to be compressed inwardly, so as to contract its inner diameter a little, and cause it to embrace the tube A very tightly. f

I provide a score across the front edge of the thim` ble l), as represented by d, which will receive a crosskey with, a strong handle to allow of turning the thimble very forcibly.` f

I correspondingly notch the end of the tube, and match the notches in the thimble and tube, so that they coincide, as represented, and turn both together.

After I have secured one of the ends of the tube very strongly by my invention, the other end may bc sniciently secured by driving in the internal thini'blc C to expand it in the ordinary manner.

, To release the tubes the several operations are reversed.

In case the tubes have been long set, and are somewhat corroded, it will require considerable force to start any part, but my invention allows great force to be applied without danger of injuring either the thin,

and sometimes soft material of the tube, or anyother part.

I make the out-er edge of my thimble D of considerable thickness, as represented, to allow the requisite force to be applied with safety.`

It will be understood that red lead, or other ordinary I or tbereabouts, may be a threaded tube, substantially as shown inV fig. 2. These threaded tubes, mounted as represented, serve as stays to aid the tube-sheets B1Bz in resisting any pressure, whether internal or external. Such have long been used, except that they have not, I think, been before scored across both the thimble and the tube.

I claim- In connection with a properly-prepared and properly-stayed tube-sheet B, the plain cylindrical tube A, and close-fitting thimble D, having a tapering threaded exterior, and plain cylindrical interior, all combined and arranged as represented.

Also, the sets of coinciding notches d, formed in 

